Delayed neutron method for measurement of fissile/fertile content of samples ranging from environmental to irradiated fuel

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6880687

Proctor, A E; Harker, Y D; Akers, D W; Mandler, J W

A delayed-neutron assay method is described which is capable of accurately determining the /sup 235/U and /sup 238/U contents of a wide range of materials. The method consists of irradiation in the Coupled Fast Reactivity Measurement Facility (CFRMF) at the Idaho National Engineering Laboratory (INEL), one position in the thermal driver area for /sup 235/U assay, and a fast neutron flux position for /sup 238/U. After irradiation, delayed neutron counting is used to measure the uranium content of the sample. By utilizing fast and thermal neutron irradiation and counting cycles, the samples /sup 238/U and /sup 235/U contents are determined. Minimal sample preparation and handling are required to obtain accurate results. The method has been used successfully on a wide range of samples, including environmental (soil) samples, irradiated and unirradiated fuel, and debris from the Three Mile Island Unit II Reactor core. Measurement precision of up to 0.5% can be achieved; sensitivity for low level samples is 9 counts min/sup -1/ nanogram/sup -1/ for /sup 235/U and 0.02 counts min/sup -1/ nanogram/sup -1/ for /sup 238/U. The fissile and/or fertile contents of samples containing /sup 233/U, /sup 239/Pu, /sup 240/Pu, /sup 237/Np, or /sup 232/Th could be determined by the same method. Data from representative samples are presented to illustrate the usefulness of these techniques.

• Research Organization: EG and G Idaho, Inc., Idaho Falls (USA)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6880687
• Report Number(s): EGG-M-16084; CONF-840734-19; ON: DE84015543
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101* -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTIVATION ANALYSIS
ALPHA DECAY RADIOISOTOPES
CFRMF REACTOR
CHEMICAL ANALYSIS
CORIUM
DELAYED NEUTRON ANALYSIS
ENERGY SOURCES
ENRICHED URANIUM REACTORS
EPITHERMAL REACTORS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL REACTORS
FAST REACTORS
FERTILE MATERIALS
FISSILE MATERIALS
FISSIONABLE MATERIALS
FUELS
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MATERIALS
MINUTES LIVING RADIOISOTOPES
NONDESTRUCTIVE ANALYSIS
NUCLEAR FUELS
NUCLEAR REACTION ANALYSIS
NUCLEI
POWER REACTORS
PWR TYPE REACTORS
RADIOISOTOPES
REACTOR MATERIALS
REACTORS
RESEARCH AND TEST REACTORS
SOILS
THERMAL REACTORS
THREE MILE ISLAND-2 REACTOR
URANIUM 235
URANIUM 238
URANIUM ISOTOPES
WATER COOLED REACTORS
WATER MODERATED REACTORS
YEARS LIVING RADIOISOTOPES
ZERO POWER REACTORS